Liquid supply system, liquid treatment device, and liquid supply method

Abstract

A liquid supply system according to one embodiment of the present disclosure comprises: a tank (71); a circulation line (72); a pump (73), a filter (76); a back pressure valve (80); and a control unit (18). The tank (71) stores a processing liquid (L). The circulation line returns, to the tank (71), the processing liquid (L) which is fed from the tank (71). The pump (73) creates a circular flow of the processing liquid (L) in the circulation line (72). The filter (76) is disposed downstream of the pump (73) in the circulation line (72). The back pressure valve (80) is disposed downstream of the filter (76) in the circulation line (72). The control unit (18) controls the system components. Furthermore, when stopping the operation of the pump (73), the control unit (18) controls the pump (73) and the back pressure valve (80) so that the pressure difference between the upstream side and downstream side of the filter (76) is no more than a prescribed threshold, within a period from when the discharge pressure of the pump (73) begins to drop to when the pump (73) stops operating.

Description

[Technical Field]

[0001] The disclosed embodiments relate to a liquid supply system, a liquid treatment apparatus, and a liquid supply method. [Background technology]

[0002] Conventionally, there has been known a liquid processing apparatus that circulates a processing liquid for substrates such as semiconductor wafers (hereinafter also referred to as wafers) through a circulation line and supplies the processing liquid to a processing section through a branch line branching from the circulation line. The circulation line of such a liquid processing apparatus is provided with a filter that removes foreign matter from the processing liquid (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-41039 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique that can prevent contamination of a treatment liquid in a circulation line. [Means for solving the problem]

[0005] A liquid supply system according to one aspect of the present disclosure includes a tank, a circulation line, a pump, a filter, a back-pressure valve, and a control unit. The tank stores a processing liquid. The circulation line returns the processing liquid sent from the tank to the tank. The pump forms a circulating flow of the processing liquid in the circulation line. The filter is provided in the circulation line downstream of the pump. The back-pressure valve is provided in the circulation line downstream of the filter. The control unit controls each component. When stopping operation of the pump, the control unit controls the pump and the back-pressure valve so that the pressure difference between the upstream and downstream sides of the filter is equal to or less than a given threshold value between the time when the pump's discharge pressure starts to decrease and the time when the pump stops operating. [Effects of the Invention]

[0006] According to the present disclosure, contamination of the treatment liquid in the circulation line can be suppressed. Note that the effects described herein are not necessarily limited to those described herein, and any of the effects described in the present disclosure may be achieved. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a processing unit according to the embodiment. [Figure 3] FIG. 3 is a diagram showing a schematic configuration of a processing liquid supply source according to the embodiment. [Figure 4] FIG. 4 is a diagram showing the transition of the differential pressure between the upstream side and the downstream side of the filter in the reference example. [Figure 5] FIG. 5 is a diagram showing the transition of the differential pressure between the upstream side and the downstream side of the filter according to the embodiment. [Figure 6] FIG. 6 is a diagram showing a schematic configuration of a processing liquid supply source according to the first modification of the embodiment. [Figure 7] FIG. 7 is a diagram showing the transition of the flow rate of the processing liquid in the circulation line according to the first modification of the embodiment. [Figure 8] FIG. 8 is a diagram showing a schematic configuration of a processing liquid supply source according to the second modification of the embodiment. [Figure 9] FIG. 9 is a diagram showing a procedure of a start-up process of a processing liquid supply source according to the second modification of the embodiment. [Figure 10] FIG. 10 is a diagram showing a procedure of a start-up process of a processing liquid supply source according to the second modification of the embodiment. [Figure 11] FIG. 11 is a diagram showing a procedure of a start-up process of a processing liquid supply source according to the second modification of the embodiment. [Figure 12] FIG. 12 is a diagram showing a schematic configuration of a processing liquid supply source according to the third modification of the embodiment. [Figure 13] FIG. 13 is a diagram showing a procedure of a start-up process of a processing liquid supply source according to the third modification of the embodiment. [Figure 14] FIG. 14 is a diagram showing a procedure of a start-up process of a processing liquid supply source according to the third modification of the embodiment. [Figure 15] FIG. 15 is a diagram showing a procedure of a start-up process of a processing liquid supply source according to the third modification of the embodiment. [Figure 16] FIG. 16 is a diagram showing a schematic configuration of a processing liquid supply source according to the fourth modification of the embodiment. [Figure 17] FIG. 17 is a flowchart showing an example of a procedure of a control process executed by the substrate processing system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, with reference to the accompanying drawings, embodiments of the liquid supply system, liquid treatment apparatus, and liquid supply method disclosed herein will be described in detail. Note that the present disclosure is not limited to the embodiments described below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of elements may differ from reality. Furthermore, the drawings may include portions with different dimensional relationships and ratios.

[0009] Conventionally, a liquid processing apparatus has been known in which a processing liquid for substrates such as semiconductor wafers (hereinafter also referred to as wafers) is circulated through a circulation line and supplied to a processing section through a branch line branching from the circulation line. The circulation line of such a liquid processing apparatus is provided with a filter for removing foreign matter from the processing liquid.

[0010] However, in conventional circulation lines, when the circulation flow of the processing liquid is stopped for maintenance or the like, there is a risk that the processing liquid in the circulation line may become contaminated by foreign matter passing through the filter due to the discharge pressure of the pump.

[0011] Therefore, there is a need for a technology that can overcome the above-mentioned problems and prevent the processing liquid in the circulation line from being contaminated.

[0012] <Outline of the substrate processing system> First, a schematic configuration of a substrate processing system 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a schematic configuration of a substrate processing system 1 according to an embodiment. The substrate processing system 1 is an example of a liquid processing apparatus. In the following, to clarify the positional relationship, mutually orthogonal X-axis, Y-axis, and Z-axis are defined, and the positive direction of the Z-axis is defined as the vertically upward direction.

[0013] 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

[0014] The loading / unloading station 2 includes a carrier placement section 11 and a transport section 12. On the carrier placement section 11, a plurality of carriers C are placed, each of which accommodates a plurality of substrates, in this embodiment, semiconductor wafers W (hereinafter referred to as wafers W), in a horizontal position.

[0015] The transfer section 12 is provided adjacent to the carrier placement section 11 and includes a substrate transfer device 13 and a transfer section 14. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 13 is capable of moving horizontally and vertically and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer section 14 using the wafer holding mechanism.

[0016] The processing station 3 is provided adjacent to the transport section 12. The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on both sides of the transport section 15.

[0017] The transfer section 15 includes a substrate transfer device 17 therein. The substrate transfer device 17 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14 and the processing unit 16 using the wafer holding mechanism.

[0018] The processing unit 16 is an example of a liquid processing section, and performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17 .

[0019] The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a storage unit 19. The storage unit 19 stores programs that control various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the storage unit 19.

[0020] Such a program may be recorded on a computer-readable storage medium and installed from that storage medium into the storage unit 19 of the control device 4. Examples of computer-readable storage media include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnetic optical disks (MOs), and memory cards.

[0021] In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading / unloading station 2 removes the wafer W from the carrier C placed on the carrier placement unit 11 and places the removed wafer W on the delivery unit 14. The wafer W placed on the delivery unit 14 is then removed from the delivery unit 14 by the substrate transfer device 17 in the processing station 3 and carried into the processing unit 16.

[0022] The wafer W carried into the processing unit 16 is processed by the processing unit 16, and then carried out of the processing unit 16 by the substrate transfer device 17 and placed on the transfer section 14. Then, the processed wafer W placed on the transfer section 14 is returned to the carrier C on the carrier placement section 11 by the substrate transfer device 13.

[0023] <Processing unit overview> Next, an overview of the processing unit 16 will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing the configuration of the processing unit 16 according to the embodiment. The processing unit 16 includes a chamber 20, a substrate processing section 30, a liquid supply section 40, and a collection cup 50.

[0024] The chamber 20 accommodates a substrate processing unit 30, a liquid supply unit 40, and a collection cup 50. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20. The FFU 21 forms a downflow within the chamber 20.

[0025] Substrate processing unit 30 includes a holder 31, a support 32, and a drive unit 33, and performs liquid processing on a placed wafer W. Holder 31 holds wafer W (see FIG. 1) horizontally. Support 32 is a member extending in the vertical direction, with its base end rotatably supported by drive unit 33, and its tip end supporting holder 31 horizontally. Drive unit 33 rotates support 32 around a vertical axis.

[0026] The substrate processing unit 30 rotates the support column 32 using the drive unit 33, thereby rotating the holder 31 supported by the support column 32. As a result, the wafer W held by the holder 31 rotates.

[0027] The liquid supply unit 40 supplies a processing liquid L (see FIG. 3) to the wafer W. The liquid supply unit 40 is connected to a processing liquid supply source 70. The liquid supply unit 40 includes a plurality of nozzles. The plurality of nozzles are provided corresponding to, for example, the plurality of types of processing liquid L. The plurality of nozzles also eject the plurality of types of processing liquid L, which are respectively supplied from the plurality of processing liquid supply sources 70, onto the wafer W.

[0028] Recovery cup 50 is disposed to surround holder 31, and collects processing liquid L that splashes from wafer W due to rotation of holder 31. A drain outlet 51 is formed at the bottom of recovery cup 50, and processing liquid L collected by recovery cup 50 is discharged from drain outlet 51 to the outside of processing unit 16.

[0029] In addition, an exhaust port 52 for discharging the gas supplied from the FFU 21 to the outside of the processing unit 16 is formed at the bottom of the collection cup 50.

[0030] <Outline of processing liquid supply source> Next, a schematic configuration of the processing liquid supply source 70 included in the substrate processing system 1 will be described with reference to Fig. 3. Fig. 3 is a diagram showing a schematic configuration of the processing liquid supply source 70 according to an embodiment. The processing liquid supply source 70 is an example of a liquid supply system.

[0031] 3, a processing liquid supply source 70 included in the substrate processing system 1 supplies processing liquid L to the multiple processing units 16. In the embodiment, for example, a processing liquid supply source 70 shown in FIG. 3 is provided for each of the multiple types of processing liquid L.

[0032] As shown in FIG. 3, the processing liquid supply source 70 includes a tank 71, a circulation line 72, a pump 73, a heater 74, a first pressure sensor 75, a filter 76, a second pressure sensor 77, a flow meter 78, multiple branch sections 79, and a back pressure valve 80.

[0033] The tank 71 stores the processing liquid L. The processing liquid L is, for example, IPA (isopropyl alcohol). Note that the processing liquid L of the present disclosure is not limited to IPA, and various types of chemical liquids can be used.

[0034] The circulation line 72 returns the treatment liquid L sent from the tank 71 to the tank 71. The circulation line 72 is provided with, in this order from the upstream side with respect to the tank 71, a pump 73, a heater 74, a first pressure sensor 75, a filter 76, a second pressure sensor 77, a flow meter 78, a plurality of branching sections 79, and a back pressure valve 80.

[0035] The pump 73 forms a circulating flow of the processing liquid L in the circulation line 72. In the embodiment, the discharge pressure of the pump 73 can be controlled by the control unit 18 (see FIG. 1).

[0036] The heater 74 is an example of a heating mechanism, and heats the processing liquid L circulating through the circulation line 72. The control unit 18 can adjust the temperature of the processing liquid L by controlling the amount of heat applied to the processing liquid L by the heater 74.

[0037] For example, the amount of heat applied to the processing liquid L by the heater 74 is adjusted based on the temperature of the processing liquid L detected by temperature sensors (not shown) provided in the tank 71 and the circulation line 72 .

[0038] The first pressure sensor 75 measures the pressure of the processing liquid L upstream of the filter 76. The filter 76 removes contaminants such as particles contained in the processing liquid L circulating in the circulation line 72.

[0039] The second pressure sensor 77 measures the pressure of the processing liquid L downstream of the filter 76. The flow meter 78 measures the flow rate of the circulating flow of the processing liquid L formed in the circulation line 72. A plurality of supply lines 100 branch off from a plurality of branching portions 79, each connected to a nozzle of a plurality of processing units 16.

[0040] The supply line 100 is provided with, in this order from the upstream side, a branching section 101 and a valve 102. A return line 103 connected to the tank 71 branches off from the branching section 101. A valve 104 is provided on the return line 103.

[0041] The valves 102 and 104 control whether or not the processing liquid L is supplied from the supply line 100 to the processing unit 16. The control unit 18 opens the valve 102 and closes the valve 104, thereby supplying the processing liquid L from the supply line 100 to the processing unit 16.

[0042] On the other hand, the control unit 18 closes the valve 102 and opens the valve 104, thereby preventing the supply of the processing liquid L from the supply line 100 to the processing unit 16. In this case, the processing liquid L in the supply line 100 returns to the tank 71 through the return line 103.

[0043] The back pressure valve 80 increases the valve opening degree when the pressure of the processing liquid L upstream of the back pressure valve 80 is greater than the desired pressure. On the other hand, the back pressure valve 80 decreases the valve opening degree when the pressure of the processing liquid L upstream of the back pressure valve 80 is smaller than the desired pressure.

[0044] As a result, the back pressure valve 80 has a function of maintaining the pressure of the processing liquid L on the upstream side at a desired pressure. In the embodiment, the valve opening degree of the back pressure valve 80 can be controlled by the control unit 18.

[0045] The tank 71 also has a processing liquid replenishment unit 81 and a drain line 82. The processing liquid replenishment unit 81 replenishes the processing liquid L into the tank 71. The drain line 82 discharges the processing liquid L in the tank 71 to the drain unit DR, for example, when replacing the processing liquid L in the tank 71.

[0046] In the processing liquid supply source 70 described above, the pressure in the multiple branch sections 79 is maintained at a desired pressure by the back pressure valve 80, thereby enabling smooth supply of processing liquid L from the processing liquid supply source 70 to each processing unit 16.

[0047] On the other hand, in the circulation line 72, when the circulation flow of the processing liquid L is stopped immediately before replacing the processing liquid L or recovering from a problem, foreign matter may pass through the filter 76 due to the discharge pressure of the pump 73, thereby contaminating the processing liquid L in the circulation line 72. Details of this problem will be described with reference to FIG.

[0048] 4 is a diagram showing the transition of the differential pressure between the upstream side and the downstream side of the filter 76 in the reference example. As shown in Fig. 4, until time T01 when the step of stopping the circulation flow starts, the control unit 18 performs the circulation step of forming a circulation flow of the treatment liquid L in the circulation line 72.

[0049] In this circulation process, the pump 73 operates at its rated output, so the discharge pressure of the pump 73 (i.e., the pressure upstream of the filter 76) is approximately constant. Also, in this circulation process, the back pressure valve 80 operates to keep the pressure upstream of the back pressure valve 80 constant, so the pressure downstream of the filter 76 is also approximately constant.

[0050] That is, in this reference example, the pressure difference between the upstream side and downstream side of the filter 76 is a substantially constant pressure difference P1.

[0051] Next, at time T01, when the step of decreasing the circulating flow of the processing liquid L in the circulation line 72 starts, the control unit 18 first turns off the control of the back pressure valve 80. This is because there is a risk of contact inside the back pressure valve 80 if the circulating flow in the circulation line 72 is stopped while the back pressure valve 80 is left on.

[0052] As a result, the back pressure valve 80 is fully opened, causing a sudden drop in pressure on the upstream side of the back pressure valve 80 (i.e., the downstream side of the filter 76). As a result, the pressure difference between the upstream side and the downstream side of the filter 76 rises suddenly, and a large pressure difference P2 that exceeds the pressure difference that the filter 76 can withstand is applied to the filter 76.

[0053] Therefore, in the reference example, due to such a large differential pressure P2, foreign matter trapped in the filter 76 may pass through the filter 76 during the drop-down process.

[0054] Next, the control unit 18 turns off the control of the backpressure valve 80 and then stops the pump 73, causing the discharge pressure of the pump 73 to gradually decrease and reach zero at time T02. As a result, the pressure upstream of the filter 76 becomes zero, and the differential pressure between the upstream and downstream sides of the filter 76 also becomes zero, completing the process of stopping the circulation flow. Then, the user performs maintenance on the processing liquid supply source 70, etc.

[0055] After the maintenance process is completed, the control unit 18 starts up the pump 73 and turns on the control of the back pressure valve 80 at time T03 in order to start up the circulation flow of the processing liquid L in the circulation line 72 (start-up process).

[0056] However, since there is a given time lag until the control of the back pressure valve 80 stabilizes, the back pressure valve 80 is not sufficiently controlled until the control stabilizes.

[0057] As a result, as shown in FIG. 4, from time T03 when the pump 73 starts to operate until time T04 when the control of the back pressure valve 80 begins to function fully, a large differential pressure P2 that exceeds the differential pressure that the filter 76 can withstand is applied between the upstream and downstream sides of the filter 76.

[0058] Therefore, in the reference example, such a large differential pressure P2 may cause foreign matter trapped in the filter 76 to pass through the filter 76 during the start-up process. Note that the circulation process starts again from time T04 when the control of the back pressure valve 80 is fully effective.

[0059] As explained above, in the reference example, when the shutdown process and startup process are performed before and after the maintenance process, the discharge pressure of the pump 73 may cause foreign matter to pass through the filter 76, thereby contaminating the processing liquid L in the circulation line 72.

[0060] Therefore, in this embodiment, the control process described below is performed to prevent contamination of the treatment liquid L in the circulation line 72. Fig. 5 is a diagram showing the transition of the differential pressure between the upstream side and the downstream side of the filter 76 according to this embodiment.

[0061] 5, until time T11 when the shut-down process of the pump 73 starts, the control unit 18 performs a circulation process in which a circulating flow of the treatment liquid L is formed in the circulation line 72. In this circulation process, similar to the above-described reference example, the differential pressure between the upstream side and the downstream side of the filter 76 becomes a substantially constant differential pressure P1.

[0062] Next, at time T11, when the step of decreasing the circulating flow of the processing liquid L in the circulation line 72 starts, the control unit 18 gradually decreases the discharge pressure of the pump 73 while keeping the control of the back pressure valve 80 on.

[0063] Furthermore, the control unit 18 controls the pump 73 and the back pressure valve 80 so that the differential pressure between the upstream side and downstream side of the filter 76 is equal to or less than a given threshold value (for example, differential pressure P1 during circulation).

[0064] In such control, the differential pressure between the upstream and downstream sides of the filter 76 is determined by measuring the pressure on the upstream side of the filter 76 with a first pressure sensor 75 and measuring the pressure on the downstream side of the filter 76 with a second pressure sensor 77.

[0065] Furthermore, the control unit 18 controls the differential pressure between the upstream and downstream sides of the filter 76 to be equal to or less than the differential pressure P1, for example, by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80.

[0066] In the embodiment, such control processing can prevent a large differential pressure exceeding the pressure differential resistance of the filter 76 during the shutdown process, thereby preventing foreign matter captured by the filter 76 from passing through the filter 76.

[0067] Therefore, according to the embodiment, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0068] In addition, in this embodiment, it is preferable to control the differential pressure between the upstream and downstream sides of the filter 76 to be equal to or less than the differential pressure P1 by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80.

[0069] This makes it possible to smoothly prevent a large differential pressure exceeding the pressure difference that the filter 76 can withstand from being applied to the filter 76. Therefore, according to the embodiment, contamination of the treatment liquid L in the circulation line 72 can be further prevented.

[0070] In addition, in the embodiment, the control unit 18 constantly monitors the first pressure sensor 75 and the second pressure sensor 77 during the circulation process before the shutdown process, and calculates in advance the maximum differential pressure between the first pressure sensor 75 and the second pressure sensor 77 during the circulation process.

[0071] Then, the control unit 18 may control the pump 73 and the back pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 during the drop-down process is equal to or less than the maximum differential pressure between the first pressure sensor 75 and the second pressure sensor 77 during the circulation process.

[0072] This prevents a differential pressure greater than that applied to the filter 76 in the most recent circulation step from being applied during the fall process, thereby further preventing foreign matter captured in the filter 76 from passing through the filter 76.

[0073] Therefore, according to the embodiment, contamination of the processing liquid L in the circulation line 72 can be further suppressed.

[0074] In the example of FIG. 5, the differential pressure between the upstream and downstream sides of the filter 76 in the drop-down process is controlled to be equal to or less than the differential pressure P1 in the circulation process, but the present disclosure is not limited to this example.

[0075] For example, in the present disclosure, the pump 73 and the back pressure valve 80 may be controlled so that the differential pressure between the upstream and downstream sides of the filter 76 during the drop-down process is equal to or less than a pressure slightly higher than the differential pressure P1 during the circulation process.

[0076] This also prevents a large differential pressure exceeding the pressure differential that the filter 76 can withstand during the shutdown process, thereby preventing foreign matter captured by the filter 76 from passing through the filter 76.

[0077] Therefore, according to the embodiment, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0078] Continuing with the description of Fig. 5, as described above, the control unit 18 controls the differential pressure between the upstream and downstream sides of the filter 76 to be equal to or less than differential pressure P1 by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80.

[0079] Then, when the valve opening of the back pressure valve 80 is fully open and the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than the differential pressure P1 (time T12), the control unit 18 determines that the discharge pressure of the pump 73 has become equal to or less than the differential pressure P1, and turns off the control of the back pressure valve 80.

[0080] Then, the control unit 18 turns off the control of the back pressure valve 80 and then stops the pump 73, causing the discharge pressure of the pump 73 to decrease and become zero at time T13. Then, the user performs maintenance on the processing liquid supply source 70, etc.

[0081] After the maintenance process is completed, the control unit 18 starts up the pump 73 and turns on the control of the back pressure valve 80 at time T14 in order to start up the circulation flow of the processing liquid L in the circulation line 72 (start-up process).

[0082] Here, in the embodiment, in order to prevent the differential pressure between the upstream and downstream sides of the filter 76 from increasing excessively until the back pressure valve 80 is fully operating, the control unit 18 operates the pump 73 so that the discharge pressure of the pump 73 gradually increases.

[0083] This prevents a large differential pressure exceeding the pressure differential resistance of the filter 76 during the start-up process, as shown in FIG. 5, and therefore prevents foreign matter captured by the filter 76 from passing through the filter 76.

[0084] Therefore, according to the embodiment, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0085] In addition, in an embodiment, during the start-up process, the pump 73 and the back pressure valve 80 may be controlled so that the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than the maximum differential pressure between the first pressure sensor 75 and the second pressure sensor 77 during the previous circulation process described above.

[0086] This prevents a differential pressure greater than that applied to the filter 76 in the most recent circulation step from being applied during the start-up step, thereby further preventing foreign matter captured by the filter 76 from passing through the filter 76.

[0087] Therefore, according to the embodiment, it is possible to further prevent contamination of the processing liquid L in the circulation line 72. In the embodiment, the circulation process is started again from time T15 when the control of the back pressure valve 80 is sufficiently effective.

[0088] <Variation 1> Next, various modifications of the substrate processing system 1 according to the embodiment will be described with reference to Figures 6 to 16. Figure 6 is a diagram showing a schematic configuration of a processing liquid supply source 70 according to Modification 1 of the embodiment.

[0089] 6, this modified example 1 differs from the above-described embodiment in that the first pressure sensor 75 and the second pressure sensor 77 are not provided in the circulation line 72. Therefore, in the following examples, the same components as those in the already-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0090] In the first modification, the control process described below is performed to prevent contamination of the processing liquid L in the circulation line 72. Fig. 7 is a diagram showing the transition of the flow rate of the processing liquid L in the circulation line 72 according to the first modification of the embodiment.

[0091] 7, until time T21 when the shut-down step of the pump 73 starts, the control unit 18 performs a circulation step of forming a circulating flow of the treatment liquid L in the circulation line 72. In this circulation step, the flow rate of the treatment liquid L in the circulation line 72 is kept at a substantially constant flow rate F1.

[0092] Next, at time T21, when the step of decreasing the circulating flow of the processing liquid L in the circulation line 72 starts, the control unit 18 gradually decreases the discharge pressure of the pump 73 while keeping the control of the back pressure valve 80 on.

[0093] Furthermore, the control unit 18 controls the pump 73 and the back pressure valve 80 so that the flow rate of the processing liquid L in the circulation line 72 is equal to or less than a given threshold value (for example, the flow rate F1 during circulation). In such control, the flow rate of the processing liquid L in the circulation line 72 can be measured by a flow meter 78.

[0094] Furthermore, the control unit 18 controls the flow rate of the treatment liquid L in the circulation line 72 to be equal to or lower than the flow rate F1, for example, by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80.

[0095] In variant 1, this control process can prevent a large flow of processing liquid from flowing through the filter 76 during the shutdown process, thereby preventing foreign matter captured by the filter 76 from passing through the filter 76.

[0096] Therefore, according to the first modification, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0097] In addition, in the first modification, the flow rate of the processing liquid L in the circulation line 72 may be controlled to be equal to or less than the flow rate F1 by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80.

[0098] This makes it possible to smoothly prevent a large flow rate of the processing liquid from flowing through the filter 76. Therefore, according to the first modification, contamination of the processing liquid L in the circulation line 72 can be further prevented.

[0099] Furthermore, in the first modification, the control unit 18 constantly monitors the flow meter 78 in the circulation step before the shut-down step, and calculates in advance the maximum flow rate of the treatment liquid L in the circulation step.

[0100] During the shut-down step, the control unit 18 may control the pump 73 and the back pressure valve 80 so that the flow rate of the processing liquid L in the circulation line 72 is equal to or less than the maximum flow rate of the processing liquid L during the circulation step.

[0101] This prevents a flow rate greater than that which flowed through the filter 76 in the most recent circulation step from flowing during the fall process, thereby further preventing foreign matter captured in the filter 76 from passing through the filter 76.

[0102] Therefore, according to the first modification, contamination of the processing liquid L in the circulation line 72 can be further suppressed.

[0103] In the example of FIG. 7, the flow rate of the treatment liquid L in the circulation line 72 in the drop-down step is controlled to be equal to or lower than the flow rate F1 in the circulation step, but the present disclosure is not limited to this example.

[0104] For example, in the present disclosure, the pump 73 and the back pressure valve 80 may be controlled in the step of decreasing the flow rate so that the flow rate of the processing liquid L in the circulation line 72 is equal to or lower than a pressure slightly higher than the flow rate F1 in the circulation step.

[0105] This also makes it possible to prevent a large flow rate of the processing liquid L from flowing through the filter 76 during the shutdown process, thereby preventing foreign matter captured by the filter 76 from passing through the filter 76.

[0106] Therefore, according to the first modification, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0107] Continuing with the description of Fig. 7, as described above, the control unit 18 controls the flow rate of the treatment liquid L in the circulation line 72 to be equal to or less than the flow rate F1 by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80.

[0108] Then, when the valve opening of the back pressure valve 80 is fully open and the flow rate of the processing liquid L in the circulation line 72 is equal to or less than the flow rate F1 (time T22), the control unit 18 determines that the flow rate of the processing liquid L in the circulation line 72 has become equal to or less than the flow rate F1, and turns off the control of the back pressure valve 80.

[0109] Then, the control unit 18 turns off the control of the back pressure valve 80 and then stops the pump 73, causing the discharge pressure of the pump 73 to decrease and become zero at time T23. Then, the user performs maintenance on the processing liquid supply source 70, etc.

[0110] After the maintenance process is completed, the control unit 18 starts up the pump 73 and turns on the control of the back pressure valve 80 at time T24 in order to start up the circulation flow of the processing liquid L in the circulation line 72 (start-up process).

[0111] Here, in variant example 1, in order to prevent the flow rate of the processing liquid L in the circulation line 72 from increasing excessively until the back pressure valve 80 is fully operating, the control unit 18 operates the pump 73 so that the discharge pressure of the pump 73 gradually increases.

[0112] This prevents a large flow of processing liquid from flowing through the filter 76 during the start-up process, as shown in FIG. 7, thereby preventing foreign matter captured by the filter 76 from passing through the filter 76.

[0113] Therefore, according to the first modification, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0114] In addition, in the first modification, the pump 73 and the back pressure valve 80 may be controlled in the start-up step so that the flow rate of the processing liquid L in the circulation line 72 is equal to or less than the maximum flow rate of the processing liquid L in the previous circulation step described above.

[0115] This prevents a flow rate greater than that which flowed through the filter 76 in the most recent circulation step from flowing during the start-up step, thereby further preventing foreign matter captured in the filter 76 from passing through the filter 76.

[0116] Therefore, according to the first modification, it is possible to further prevent contamination of the processing liquid L in the circulation line 72. In the first modification, the circulation process is started again from time T25 when the control of the back pressure valve 80 is sufficiently effective.

[0117] <Variation 2> 8 is a diagram showing a schematic configuration of a processing liquid supply source 70 according to Modification 2 of the embodiment. As shown in Fig. 8, in Modification 2, a pump 73, a heater 74, a branching portion 83, a valve 85, a first pressure sensor 75, a filter 76, and a second pressure sensor 77 are provided in circulation line 72, in that order from upstream to downstream with respect to tank 71. Furthermore, a flow meter 78, a branching portion 87, a valve 89, a plurality of branching portions 79, and a back pressure valve 80 are provided in circulation line 72, in that order from upstream to downstream with respect to second pressure sensor 77.

[0118] A branch circulation line 84 connected to the tank 71 branches off from the branch part 83. A valve 86 is provided on the branch circulation line 84. A drain line 88 connected to the drain part DR branches off from the branch part 87. A valve 90 is provided on the drain line 88.

[0119] Next, the start-up process according to Modification 2 will be described in detail with reference to Fig. 9 to Fig. 11. Fig. 9 to Fig. 11 are diagrams showing the procedure of the start-up process of the processing liquid supply source 70 according to Modification 2 of the embodiment. Note that Fig. 9 to Fig. 11 omit illustration of the processing unit 16 and the like.

[0120] 9, in the start-up process according to Modification 2, control unit 18 (see FIG. 1) first operates pump 73 and heater 74, closes valve 85, and opens valve 86. In the following drawings, an "O" is given to a valve in an open state, and a "C" is given to a valve in a closed state.

[0121] 9, a circulation flow of the processing liquid L is formed in the processing liquid supply source 70, passing through the circulation line 72 and the branch circulation line 84. By maintaining the circulation flow indicated by the bold dashed line while operating the heater 74, the processing liquid L in the tank 71 can be heated to a desired temperature.

[0122] Here, in variant example 2, by raising the temperature of the processing liquid L while forming a circulation flow of the processing liquid L flowing through the circulation line 72 and the branch circulation line 84, the temperature raising process of the processing liquid L can be performed in the start-up process without passing it through the filter 76.

[0123] Therefore, according to the second modification, contamination of the processing liquid L by particles passing through the filter 76 can be prevented as the temperature of the processing liquid L increases. Moreover, in the second modification, the processing liquid L does not flow through the filter 76 where particles are trapped, so contamination of the processing liquid L during the temperature increase process can be suppressed. Furthermore, in the second modification, pressure loss in the filter 76 during the temperature increase process can be avoided, so the temperature of the processing liquid L can be increased efficiently.

[0124] Then, when the temperature of the processing liquid L in the tank 71 reaches a given temperature, as shown in FIG. 10, the control unit 18 (see FIG. 1) maintains the operation of the pump 73 and the heater 74, opens the valves 85, 86, and 90, and closes the valve 89.

[0125] As a result, as shown by the bold dashed line in Figure 10, a circulation flow of the processing liquid L continues to be formed through the circulation line 72 and the branch circulation line 84, and the processing liquid L being heated is discharged to the drain section DR via the drain line 88.

[0126] As a result, when the processing liquid L is heated and flows through the filter 76, the filter 76 heats up and becomes coarse, and even if particles captured by the filter 76 pass through the filter 76, the particles can be prevented from returning to the tank 71.

[0127] Therefore, according to the second modification, the processing liquid L containing a large number of particles that has passed through the filter 76 can be prevented from diffusing into the circulation line 72 and returning to the tank 71.

[0128] Then, the amount of liquid discharged from the drain line 88, which is determined based on the measurement value of the flow meter 78, reaches a given amount, and fewer particles pass through the filter 76. Then, as shown in Fig. 11, the control unit 18 (see Fig. 1) maintains the operation of the pump 73 and the heater 74, opens the valves 85 and 89, and closes the valves 86 and 90.

[0129] As a result, as shown by the bold dashed line in Fig. 11, a circulating flow of the processing liquid L is formed in the processing liquid supply source 70 through the circulation line 72. Note that, before the stage shown in Fig. 11, the control of the back pressure valve 80 has already been turned on.

[0130] In the second modification, the processing liquid L in the circulation line 72 can be prevented from being contaminated by performing the same control processing in the start-up process as in the above-described embodiment.

[0131] Furthermore, in Modification 2, after the temperature raising process of the processing liquid L is completed, the high-temperature processing liquid L is passed through the filter 76, thereby preventing the temperature of the filter 76 from returning to room temperature. In this way, by gradually raising the temperature of the filter 76, which has returned to room temperature, to a given high temperature by the temperature raising process, the mesh of the filter 76 becomes coarse, preventing many particles from passing through the filter 76.

[0132] Therefore, according to the second modification, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0133] In the second modification, the drainage line 88 is preferably connected not directly to the filter 76 but to the circulation line 72 downstream of the filter 76 (here, to the branching portion 87).

[0134] If the drain line 88 is directly connected to the filter 76, it is very difficult to cause all of the processing liquid L that has flowed through the inside of the filter 76 to flow into the drain line 88. On the other hand, in Modification 2, by connecting the drain line 88 to the circulation line 72 downstream of the filter 76, it is possible to cause all of the processing liquid L that has flowed through the inside of the filter 76 to flow into the drain line 88.

[0135] Therefore, according to the second modification, contamination of the processing liquid L in the circulation line 72 can be further suppressed.

[0136] In addition, in the second modification, it is preferable that the flow meter 78 is positioned between the filter 76 and the drain line 88 (i.e., the branch portion 87) in the circulation line 72. This allows the control unit 18 to accurately monitor the amount of the discharged processing liquid L based on the value of the flow meter 78 in the step of discharging the processing liquid L to the drain portion DR via the drain line 88 shown in FIG.

[0137] Therefore, according to variant example 2, in the process of discharging the processing liquid L into the drain section DR via the drain line 88, excessive discharge of the processing liquid L can be suppressed, thereby reducing the wasteful disposal of the processing liquid L.

[0138] In the above-described modified example 2, as shown in FIG. 10, a circulating flow of the processing liquid L is formed through the circulation line 72 and the branch circulation line 84, and the processing liquid L being heated is discharged to the drain section DR via the drain line 88. However, the present disclosure is not limited to this example.

[0139] 9, the control unit 18 maintains the operation of the pump 73 and the heater 74, opens the valves 85 and 90, and closes the valves 86 and 89. As a result, the control unit 18 may discharge the processing liquid L, for which the temperature increase processing has been completed, into the drain unit DR via the drain line 88.

[0140] As a result, when the heated processing liquid L flows through the filter 76, the filter 76 heats up and becomes coarse, and even if particles captured by the filter 76 pass through the filter 76, the particles can be prevented from returning to the tank 71.

[0141] In this case, it is preferable to move to the process shown in FIG. 11 after the processing liquid L, for which the temperature raising process has been completed, has been discharged to the drain portion DR via the drain line 88 for a predetermined time.

[0142] Furthermore, in the above-described variant example 2, an example is shown in which the processing liquid L undergoing temperature increase is discharged to the drain section DR via the drain line 88 as shown in FIG. 10, and then a circulating flow of the processing liquid L is formed through the circulation line 72 as shown in FIG. 11, but the present disclosure is not limited to such an example.

[0143] For example, following the process shown in FIG. 10, the control unit 18 may repeat the process shown in FIG. 9 and the process shown in FIG. 10 multiple times.

[0144] As a result, the flow rate of the processing liquid L flowing through the filter 76 in the process shown in FIG. 9 can be returned to zero, and then the processing liquid L can be passed through the filter 76 again in the process shown in FIG. 10, so that more particles that had been captured in the filter 76 can be flowed downstream.

[0145] Therefore, according to the second modification, contamination of the processing liquid L in the circulation line 72 can be further suppressed.

[0146] Furthermore, in the above-described variant example 2, an example is shown in which the processing liquid L is circulated through the branch circulation line 84, the processing liquid L is heated to a desired temperature, and then the processing liquid L is drained through the drain line 88. However, the present disclosure is not limited to such an example.

[0147] For example, in the present disclosure, while circulating the processing liquid L through the branch circulation line 84, a predetermined amount of the processing liquid L may be first discharged through the drain line 88 without raising the temperature of the processing liquid L to a desired temperature, and then the processing liquid L may be circulated through the circulation line 72. This also makes it possible to prevent the processing liquid L in the circulation line 72 from being contaminated.

[0148] <Variation 3> 12 is a diagram showing a schematic configuration of a processing liquid supply source 70 according to Modification 3 of the embodiment. As shown in Fig. 12, Modification 3 differs from Modification 2 in the configuration of a branch circulation line 84.

[0149] Specifically, in the third modification, the branch circulation line 84 has a bypass line 91. The bypass line 91 is connected to the branch circulation line 84 between the upstream side of the valve 86 and the downstream side of the valve 86.

[0150] Further, an orifice 92 is provided in the bypass line 91. The orifice 92 reduces the flow rate of the processing liquid L flowing through the bypass line 91. The bypass line 91 and the orifice 92 are an example of a flow rate adjusting mechanism.

[0151] Next, the start-up process according to Modification 3 will be described in detail with reference to Figures 13 to 15. Figures 13 to 15 are diagrams showing the procedure of the start-up process of the processing liquid supply source 70 according to Modification 3 of the embodiment. Note that in Figures 13 to 15, the processing unit 16 and the like are not shown.

[0152] As shown in FIG. 13, in the start-up process according to the third modification, the control unit 18 (see FIG. 1) first operates the pump 73 and the heater 74, closes the valve 85, and opens the valve 86.

[0153] 13, a circulation flow of the processing liquid L is formed in the processing liquid supply source 70, passing through the circulation line 72 and the branch circulation line 84. In the process shown in FIG. 13, the processing liquid L passes through both the branch circulation line 84 and the bypass line 91, and therefore the flow rate of the processing liquid L in the branch circulation line 84 is large.

[0154] Then, by operating the heater 74 and maintaining the circulating flow indicated by the bold dashed line, the temperature of the processing liquid L in the tank 71 can be raised to a desired temperature.

[0155] Here, in variant example 3, by raising the temperature of the processing liquid L while forming a circulation flow of the processing liquid L flowing through the circulation line 72 and the branch circulation line 84, the temperature raising process of the processing liquid L can be performed in the start-up process without passing it through the filter 76.

[0156] Therefore, according to the third modification, contamination of the processing liquid L by particles passing through the filter 76 can be prevented as the temperature of the processing liquid L increases. Moreover, in the third modification, the processing liquid L does not flow through the filter 76 where particles are trapped, so contamination of the processing liquid L during the temperature increase process can be suppressed. Furthermore, in the third modification, pressure loss in the filter 76 during the temperature increase process can be avoided, so the temperature of the processing liquid L can be increased efficiently.

[0157] Then, when the temperature of the processing liquid L in the tank 71 reaches a given temperature, as shown in FIG. 14, the control unit 18 (see FIG. 1) maintains the operation of the pump 73 and the heater 74, opens the valves 85, 86, and 90, and closes the valve 89.

[0158] 14, a circulating flow of the processing liquid L passing through the circulation line 72 and the branch circulation line 84 is continuously formed, and the processing liquid L being heated is discharged to the drain section DR via the drain line 88. In the process shown in FIG. 14, the processing liquid L passes through both the branch circulation line 84 and the bypass line 91, and therefore the flow rate of the processing liquid L in the branch circulation line 84 is large.

[0159] As a result, when the processing liquid L is heated and flows through the filter 76, the filter 76 heats up and becomes coarse, and even if particles captured by the filter 76 pass through the filter 76, the particles can be prevented from returning to the tank 71.

[0160] Therefore, according to the third modification, the processing liquid L containing a large number of particles that has passed through the filter 76 can be prevented from diffusing into the circulation line 72 and returning to the tank 71.

[0161] Then, after a given time has passed and fewer particles are passing through the filter 76, the control unit 18 (see FIG. 1) maintains the operation of the pump 73 and the heater 74, opens the valves 85 and 89, and closes the valves 86 and 90, as shown in FIG. 15.

[0162] As a result, as shown by the bold dashed line in Figure 14, a circulating flow of processing liquid L is formed in the processing liquid supply source 70 through the circulation line 72, and a circulating flow of processing liquid L is continuously formed through the circulation line 72 and the branch circulation line 84.

[0163] Note that the control of the back pressure valve 80 is already on before the stage shown in Fig. 15. In addition, in the process shown in Fig. 15, the processing liquid L flows only through the bypass line 91 in the branch circulation line 84, so the flow rate of the processing liquid L in the branch circulation line 84 is small.

[0164] In the third modification, the processing liquid L in the circulation line 72 can be prevented from being contaminated by performing the same control processing in the start-up process as in the above-described embodiment.

[0165] Furthermore, in Modification 3, after the temperature raising process of the processing liquid L is completed, the high-temperature processing liquid L is passed through the filter 76, thereby preventing the temperature of the filter 76 from returning to room temperature. In this way, by gradually raising the temperature of the filter 76, which has returned to room temperature, to a given high temperature by the temperature raising process, the mesh of the filter 76 becomes coarse, and it is possible to prevent many particles from passing through the filter 76.

[0166] Therefore, according to the third modification, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0167] 15 , in the process of circulating the processing liquid L in the circulation line 72, a small circulation flow is also formed in the branch circulation line 84. This makes it possible to prevent the processing liquid L from accumulating in the branch circulation line 84 while the processing liquid L is circulating in the circulation line 72.

[0168] That is, in the third modification, when the maintenance process for the processing liquid supply source 70 or the like is performed again and then the circulation flow start-up process is performed again, the branch circulation line 84 in which the processing liquid L had been stagnating can be used to prevent the processing liquid L from being contaminated with particles or the like.

[0169] Therefore, according to the third modification, contamination of the processing liquid L in the circulation line 72 can be suppressed.

[0170] In addition, in variant example 3, as shown in Figure 15, when circulating the processing liquid L in the circulation line 72, it is preferable to circulate the processing liquid L in the branch circulation line 84 at a flow rate smaller than that before starting circulation of the processing liquid L in the circulation line 72.

[0171] This makes it possible to maintain both the circulation flow in the circulation line 72 and the circulation flow in the branch circulation line 84 without excessively increasing the rated flow rate of the pump 73. Therefore, according to the third modification, the manufacturing cost of the processing liquid supply source 70 can be reduced.

[0172] In the examples of FIGS. 12 to 15, the bypass line 91 and the orifice 92 are used as the flow rate adjusting mechanism of the branch circulation line 84, but the present disclosure is not limited to such examples.

[0173] For example, two or more types of valves capable of controlling the valve opening degree may be provided in the branch circulation line 84, and the control unit 18 may adjust the flow rate of the processing liquid L in the branch circulation line 84 by controlling the valve opening degree of such valves.

[0174] This also makes it possible to prevent the processing liquid L from being contaminated with particles and the like by using the branched circulation line 84 in which the processing liquid L was stagnating when the circulation flow start-up process is performed again, thereby suppressing contamination of the processing liquid L in the circulation line 72.

[0175] <Variation 4> 16 is a diagram showing a schematic configuration of a processing liquid supply source 70 according to Modification 4 of the embodiment. As shown in Fig. 16, Modification 4 differs from Modification 2 in the configuration downstream of the drainage line 88.

[0176] Specifically, in the fourth modification, the drain line 88 is connected to a recovery mechanism 110 instead of to a drain section DR (see FIG. 8 ). The recovery mechanism 110 includes a recovery tank 111, a circulation line 112, a pump 113, a flow meter 114, a filter 115, a branch section 116, and a valve 117. The filter 115 is an example of a filtering mechanism.

[0177] The recovery tank 111 recovers and stores the treatment liquid L discharged from the drain line 88. The circulation line 112 returns the treatment liquid L sent from the recovery tank 111 to the recovery tank 111. The circulation line 112 is provided with a pump 113, a flow meter 114, a filter 115, a branching section 116, and a valve 117, in this order from the upstream side with respect to the recovery tank 111.

[0178] The pump 113 forms a circulating flow of the processing liquid L in the circulation line 112. The flow meter 114 measures the flow rate of the circulating flow of the processing liquid L formed in the circulation line 112. The filter 115 removes contaminants such as particles contained in the processing liquid L circulating inside the circulation line 112.

[0179] A return line 118 that is connected to the tank 71 branches off from the branching portion 116. A valve 119 is provided on the return line 118.

[0180] In the fourth modification, the processing liquid L discharged from the drain line 88 is collected by the collection mechanism 110, and the processing liquid L is filtered by this collection mechanism.

[0181] Specifically, the control unit 18 (see FIG. 1) operates the pump 113 to form a circulating flow of the treatment liquid L in the circulation line 112, and repeatedly passes the circulating treatment liquid L through the filter 115 to filter the treatment liquid L. At this time, the control unit 18 opens the valve 117 and closes the valve 119.

[0182] When the processing liquid L in the recovery tank 111 reaches a given cleanliness level, the control unit 18 closes the valve 117 and opens the valve 119. This causes the control unit 18 to return the clean, filtered processing liquid L from the recovery tank 111 to the tank 71 via the circulation line 112 and the return line 118.

[0183] This reduces the amount of processing liquid L discarded into the drain portion DR. Therefore, according to the fourth modification, the amount of processing liquid L used can be reduced, thereby reducing the processing cost of the wafer W.

[0184] In addition, in Modification 4, the temperature of the processing liquid L circulating through the circulation line 112 may be lower than the temperature of the processing liquid L circulating through the circulation line 72. For example, the temperature of the processing liquid L circulating through the circulation line 112 may be room temperature.

[0185] This allows a larger number of particles to aggregate in the treatment liquid L circulating through the circulation line 112. Therefore, according to the fourth modification, the treatment liquid L can be efficiently filtered in the recovery mechanism 110.

[0186] The liquid supply system (processing liquid supply source 70) according to the embodiment includes a tank 71, a circulation line 72, a pump 73, a filter 76, a back-pressure valve 80, and a control unit 18. The tank 71 stores the processing liquid L. The circulation line 72 returns the processing liquid L sent from the tank 71 to the tank 71. The pump 73 generates a circulating flow of the processing liquid L in the circulation line 72. The filter 76 is provided in the circulation line 72 downstream of the pump 73. The back-pressure valve 80 is provided in the circulation line 72 downstream of the filter 76. The control unit 18 controls each component. When stopping the operation of the pump 73, the control unit 18 controls the pump 73 and the back-pressure valve 80 so that the pressure difference between the upstream and downstream sides of the filter 76 is equal to or less than a predetermined threshold value during the period from when the discharge pressure of the pump 73 starts to decrease until the operation of the pump 73 is stopped. This prevents contamination of the processing liquid L in the circulation line 72.

[0187] Furthermore, in the liquid supply system (processing liquid supply source 70) according to this embodiment, the control unit 18 controls the differential pressure between the upstream and downstream sides of the filter 76 to be equal to or less than a given threshold value by decreasing the discharge pressure of the pump 73 and increasing the valve opening of the back pressure valve 80. This further prevents the processing liquid L in the circulation line 72 from being contaminated.

[0188] Furthermore, in the liquid supply system (processing liquid supply source 70) according to this embodiment, when stopping the operation of the pump 73, the control unit 18 controls the pump 73 and the back pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than a maximum differential pressure. This maximum differential pressure is the maximum differential pressure between the upstream and downstream sides of the filter 76 when a circulating flow of the processing liquid L is formed in the circulation line 72. This further prevents contamination of the processing liquid L in the circulation line 72.

[0189] The liquid supply system (processing liquid supply source 70) according to this embodiment further includes a first pressure sensor 75 provided upstream of the filter 76 and a second pressure sensor 77 provided downstream of the filter 76. The control unit 18 calculates the maximum differential pressure between the first pressure sensor 75 and the second pressure sensor 77 when a circulating flow of the processing liquid L is formed in the circulation line 72. Furthermore, when stopping the operation of the pump 73, the control unit 18 controls the pump 73 and the back-pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than the maximum differential pressure. This further prevents contamination of the processing liquid L in the circulation line 72.

[0190] Furthermore, in the liquid supply system (processing liquid supply source 70) according to this embodiment, when starting circulation of the processing liquid L in the circulation line 72, the control unit 18 controls the pump 73 and the back pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than a maximum differential pressure. This maximum differential pressure is the maximum differential pressure between the upstream and downstream sides of the filter 76 when a circulating flow of the processing liquid L is formed in the circulation line 72. This makes it possible to further prevent contamination of the processing liquid L in the circulation line 72.

[0191] The liquid supply system (processing liquid supply source 70) according to this embodiment further includes a heating mechanism (heater 74) and a branch circulation line 84. The heating mechanism (heater 74) is provided in the circulation line 72 between the pump 73 and the filter 76. The branch circulation line 84 branches off from the circulation line 72 between the heating mechanism (heater 74) and the filter 76, and returns the processing liquid L sent from the tank 71 to the tank 71. Before starting circulation of the processing liquid L in the circulation line 72, the control unit 18 operates the pump 73 to circulate the processing liquid L through the branch circulation line 84, while heating the processing liquid L with the heating mechanism (heater 74). This makes it possible to suppress contamination of the processing liquid L during the temperature-raising process.

[0192] The liquid supply system (processing liquid supply source 70) according to the embodiment further includes a branching section 79, a valve 89, and a drainage line 88. The branching section 79 is located downstream of the filter 76 in the circulation line 72, and a supply line 100 that supplies the processing liquid L to the substrate processing unit 30 branches off from the branching section 79. The valve 89 is provided between the filter 76 and the branching section 79. The drainage line 88 is connected to the circulation line 72 between the filter 76 and the valve 89. Before starting circulation of the processing liquid L in the circulation line 72, the control unit 18 closes the valve 89 and heats the processing liquid L with the heating mechanism (heater 74) while circulating it through the branched circulation line 84. After heating with the heating mechanism (heater 74), the control unit 18 drains the processing liquid L from the drainage line 88. This prevents the processing liquid L, which contains a large number of particles and has passed through the filter 76, from diffusing into the circulation line 72 and returning to the tank 71.

[0193] Furthermore, in the liquid supply system (processing liquid supply source 70) according to this embodiment, the control unit 18 alternately circulates the processing liquid L through the branch circulation line 84 and drains the processing liquid from the drain line 88 before starting circulation of the processing liquid L through the circulation line 72. This further prevents the processing liquid L in the circulation line 72 from being contaminated.

[0194] The liquid supply system (processing liquid supply source 70) according to this embodiment further includes a flow meter 78 provided between the filter 76 and the valve 89. The drain line 88 is connected to the circulation line 72 downstream of the flow meter 78. The control unit 18 monitors the amount of processing liquid L drained from the drain line 88 using the flow meter 78. This makes it possible to reduce wasteful disposal of processing liquid L.

[0195] Furthermore, in the liquid supply system (processing liquid supply source 70) according to this embodiment, when the amount of drained liquid reaches a predetermined amount, the control unit 18 opens the valve 90 to cause the processing liquid L to flow through the circulation line 72, thereby forming a circulation flow. This makes it possible to reduce wasteful disposal of the processing liquid L.

[0196] Furthermore, in the liquid supply system (processing liquid supply source 70) according to the embodiment, the control unit 18 circulates the processing liquid L in the branch circulation line 84 while circulating the processing liquid L in the circulation line 72. This makes it possible to prevent the processing liquid L in the circulation line 72 from being contaminated.

[0197] Moreover, the liquid supply system (processing liquid supply source 70) according to the embodiment further includes a flow rate adjustment mechanism (bypass line 91 and orifice 92) that is provided in the branch circulation line 84 and adjusts the flow rate of the processing liquid L flowing through the branch circulation line 84. Furthermore, when circulating the processing liquid L through the circulation line 72, the control unit 18 circulates the processing liquid L through the branch circulation line 84 at a flow rate that is smaller than the flow rate before starting circulation of the processing liquid L through the circulation line 72. This allows the manufacturing cost of the processing liquid supply source 70 to be reduced.

[0198] Moreover, the liquid supply system (processing liquid supply source 70) according to the embodiment further includes a recovery tank 111, a filtering mechanism (filter 115), and a return line 118. The recovery tank 111 recovers the processing liquid L flowing through the drain line 88. The filtering mechanism (filter 115) filters the processing liquid L recovered in the recovery tank 111. The return line 118 connects the filtering mechanism (filter 115) and the tank 71, and returns the processing liquid L filtered by the filtering mechanism (filter 115) to the tank 71. This reduces the cost of processing the wafers W.

[0199] Moreover, the liquid supply system (processing liquid supply source 70) according to this embodiment further includes a branching section 79, a valve 89, and a drainage line 88. The branching section 79 is located downstream of the filter 76 in the circulation line 72, and a supply line 100 that supplies the processing liquid L to the substrate processing unit 30 branches off from the branching section 79. The valve 89 is provided between the filter 76 and the branching section 79. The drainage line 88 is connected to the circulation line 72 between the filter 76 and the valve 89. Furthermore, before starting circulation of the processing liquid L in the circulation line 72, the control unit 18 closes the valve 89 to drain the processing liquid L from the drainage line 88. This prevents the processing liquid L, which contains a large number of particles and has passed through the filter 76, from diffusing into the circulation line 72 and returning to the tank 71.

[0200] The liquid supply system (processing liquid supply source 70) according to the embodiment includes a tank 71, a circulation line 72, a pump 73, a filter 76, a back-pressure valve 80, and a control unit 18. The tank 71 stores the processing liquid L. The circulation line 72 returns the processing liquid L sent from the tank 71 to the tank 71. The pump 73 generates a circulation flow of the processing liquid L in the circulation line 72. The filter 76 is provided in the circulation line 72 downstream of the pump 73. The back-pressure valve 80 is provided in the circulation line 72 downstream of the filter 76. The control unit 18 controls each component. When stopping the operation of the pump 73, the control unit 18 controls the pump 73 and the back-pressure valve 80 so that the flow rate of the processing liquid L flowing through the circulation line 72 is equal to or less than a given threshold value during the period from when the discharge pressure of the pump 73 starts to decrease until the operation of the pump 73 is stopped. This prevents the processing liquid L in the circulation line 72 from being contaminated.

[0201] Furthermore, the liquid processing apparatus (substrate processing system 1) according to the embodiment includes a liquid processing section (processing unit 16) and a supply line 100. The liquid processing section (processing unit 16) processes a substrate (wafer W) with a processing liquid L. The supply line 100 supplies the processing liquid L from the liquid supply system (processing liquid supply source 70) described above to the liquid processing section (processing unit 16). This allows the wafer W to be processed in the processing liquid supply source 70 with the processing liquid L whose contamination has been suppressed.

[0202] <Control processing procedure> Next, the procedure of the control process according to the embodiment will be described with reference to Fig. 17. Fig. 17 is a flowchart showing an example of the procedure of the control process executed by the substrate processing system 1 according to the embodiment.

[0203] In the control process according to the embodiment, the control unit 18 operates the pump 73 and the heater 74 to circulate the treatment liquid L in the circulation line 72 (step S101). In the process of step S101, the control unit 18 also operates the first pressure sensor 75 and the second pressure sensor 77 to determine the maximum differential pressure between the upstream and downstream sides of the filter 76.

[0204] In the process of step S101, the control unit 18 may operate the flow meter 78 to determine the maximum flow rate of the treatment liquid L in the circulation line 72.

[0205] Next, the control unit 18 stops the circulation flow of the treatment liquid L in the circulation line 72 (step S102). At this time, the control unit 18 controls the pump 73 and the back-pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 becomes equal to or less than a given threshold value (for example, the maximum differential pressure between the upstream and downstream sides of the filter 76 in the process of step S101).

[0206] In addition, in the processing of step S102, the control unit 18 may control the pump 73 and the back pressure valve 80 so that the flow rate of the processing liquid L in the circulation line 72 is equal to or less than a given threshold value (for example, the maximum flow rate of the processing liquid L in the processing of step S101).

[0207] Next, maintenance steps such as cleaning the inside of the tank 71, replacing the processing liquid L, and repairing any problems are performed (step S103). Then, the control unit 18 starts a circulation flow of the processing liquid L in the circulation line 72 (step S104).

[0208] At this time, the control unit 18 operates the pump 73 so as to gradually increase the discharge pressure of the pump 73. Furthermore, in the process of step S104, the control unit 18 may control the pump 73 and the back pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than the maximum differential pressure between the first pressure sensor 75 and the second pressure sensor 77 in the circulation process described above.

[0209] Furthermore, in the process of step S104, the control unit 18 may control the pump 73 and the back pressure valve 80 so that the flow rate of the processing liquid L in the circulation line 72 is equal to or less than the maximum flow rate of the processing liquid L in the above-mentioned circulation step.

[0210] Then, when the control of the back pressure valve 80 is fully functioning, the process returns to the circulation step of the processing liquid L again (step S105), and the series of control processes ends.

[0211] The liquid supply method according to the embodiment includes a step of forming a circulating flow (step S101), a step of decreasing the circulating flow (step S102), and a step of increasing the circulating flow (step S104). The step of forming a circulating flow (step S101) operates pump 73 to form a circulating flow of processing liquid L in circulation line 72, which returns processing liquid L sent from tank 71 to tank 71. The step of decreasing the circulating flow (step S102) decreases the circulating flow of processing liquid L in circulation line 72. The step of increasing the circulating flow (step S104) increases the circulating flow of processing liquid L in circulation line 72. The step of decreasing the circulating flow, when stopping the operation of pump 73, controls pump 73 and backpressure valve 80 so that the pressure difference between the upstream and downstream sides of filter 76 is equal to or less than a given threshold value during the period from when the discharge pressure of pump 73 starts to decrease until the operation of pump 73 is stopped. The filter 76 is provided in the circulation line 72 downstream of the pump 73. The back pressure valve 80 is provided in the circulation line 72 downstream of the filter 76. This makes it possible to prevent the processing liquid L in the circulation line 72 from being contaminated.

[0212] Furthermore, in the liquid supply method according to the embodiment, the step of stopping the circulating flow (step S102) controls pump 73 and back-pressure valve 80 so that the differential pressure between the upstream and downstream sides of filter 76 is equal to or less than the maximum differential pressure when pump 73 is stopped. This maximum differential pressure is the maximum differential pressure between the upstream and downstream sides of filter 76 in the step of forming the circulating flow (step S101). This makes it possible to prevent contamination of treatment liquid L in circulation line 72.

[0213] Furthermore, in the liquid supply method according to the embodiment, the step of starting up a circulation flow (step S104) controls the pump 73 and the back-pressure valve 80 so that the differential pressure between the upstream and downstream sides of the filter 76 is equal to or less than a maximum differential pressure when starting circulation of the processing liquid L in the circulation line 72. This maximum differential pressure is the maximum differential pressure between the upstream and downstream sides of the filter 76 in the step of forming a circulation flow (step S101). This makes it possible to prevent contamination of the processing liquid L in the circulation line 72.

[0214] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0215] The disclosed embodiments should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0216] W wafer 1. Substrate processing system (an example of a liquid processing device) 16 Processing unit (an example of a liquid processing unit) 18 Control Unit 30 Substrate processing section 70 Processing liquid supply source (an example of a liquid supply system) 71 Tank 72 Circulation Line 73 Pump 74 Heater (an example of a heating mechanism) 75 First pressure sensor 76 filters 77 Second pressure sensor 78 Flow meter 79 Branch 80 Back pressure valve 84 Branch circulation line 88 Drainage Line 89 Valve 91 Bypass line (an example of a flow control mechanism) 92 Orifice (an example of a flow rate adjustment mechanism) 100 Supply Lines 110 Recovery Mechanism 111 Recovery Tank 115 Filter (an example of a filtering mechanism) 118 Return Line L processing liquid

Claims

1. a tank for storing a processing liquid; a circulation line that returns the treatment liquid sent from the tank to the tank; a pump that generates a circulating flow of the treatment liquid in the circulation line; a filter provided in the circulation line downstream of the pump; a back pressure valve provided in the circulation line downstream of the filter; a control unit that controls each unit; Equipped with When stopping the operation of the pump, the control unit controls the pump and the back pressure valve so that the differential pressure between the upstream side and the downstream side of the filter becomes equal to or less than a given threshold value during the period from when the discharge pressure of the pump starts to decrease until the operation of the pump stops. Fluid supply system.

2. The control unit controls the differential pressure between the upstream side and the downstream side of the filter to be equal to or less than a given threshold value by decreasing the discharge pressure of the pump and increasing the valve opening of the back pressure valve. The liquid delivery system of claim 1 .

3. When stopping the operation of the pump, the control unit controls the pump and the back pressure valve so that a differential pressure between the upstream side and the downstream side of the filter is equal to or less than a maximum differential pressure between the upstream side and the downstream side of the filter when a circulating flow of the treatment liquid is formed in the circulation line. The liquid supply system according to claim 1 or 2.

4. a first pressure sensor provided upstream of the filter; a second pressure sensor provided downstream of the filter; Furthermore, The control unit calculating a maximum differential pressure between the first pressure sensor and the second pressure sensor when a circulating flow of the treatment liquid is formed in the circulation line; When the operation of the pump is stopped, the pump and the back pressure valve are controlled so that the differential pressure between the upstream side and the downstream side of the filter is equal to or less than the maximum differential pressure. The liquid supply system according to claim 1 or 2.

5. The control unit controls the pump and the back pressure valve so that, when starting circulation of the treatment liquid in the circulation line, a differential pressure between the upstream side and the downstream side of the filter becomes equal to or less than a maximum differential pressure between the upstream side and the downstream side of the filter when a circulating flow of the treatment liquid in the circulation line is formed. The liquid supply system according to claim 1 or 2.

6. a heating mechanism provided in the circulation line between the pump and the filter; a branch circulation line that branches off from the circulation line between the heating mechanism and the filter and returns the treatment liquid sent from the tank to the tank; Furthermore, The control unit operates the pump to circulate the treatment liquid through the branch circulation line while heating the treatment liquid with the heating mechanism before starting circulation of the treatment liquid through the circulation line. The liquid supply system according to claim 1 or 2.

7. a branching portion in the circulation line downstream of the filter, from which a supply line for supplying the processing liquid to a substrate processing unit branches; a valve provided between the filter and the branching portion; a drainage line connected between the filter and the valve in the circulation line; Furthermore, The control unit closes the valve before starting circulation of the treatment liquid in the circulation line, and heats the treatment liquid with the heating mechanism while circulating the treatment liquid in the branch circulation line, and after heating with the heating mechanism, drains the treatment liquid from the drain line. The liquid delivery system of claim 6.

8. The control unit repeats circulation in the branch circulation line and drainage from the drain line before starting circulation of the treatment liquid in the circulation line. The liquid delivery system of claim 7.

9. a flow meter disposed between the filter and the valve; the drain line is connected to the circulation line downstream of the flow meter; The control unit monitors the amount of the processing liquid discharged from the drain line using the flow meter. The liquid delivery system of claim 7.

10. When the amount of the drained liquid reaches a predetermined amount, the control unit opens the valve to allow the processing liquid to flow through the circulation line, thereby forming a circulation flow. The liquid delivery system of claim 9.

11. The control unit circulates the treatment liquid in the branch circulation line while circulating the treatment liquid in the circulation line. The liquid delivery system of claim 6.

12. a flow rate adjusting mechanism provided in the branch circulation line to adjust the flow rate of the treatment liquid flowing through the branch circulation line, When circulating the treatment liquid in the circulation line, the control unit circulates the treatment liquid in the branch circulation line at a flow rate smaller than that before starting circulation of the treatment liquid in the circulation line. The liquid delivery system of claim 11.

13. a recovery tank that recovers the treatment liquid flowing through the drain line; a filtering mechanism that filters the treatment liquid recovered in the recovery tank; a return line connecting the filtration mechanism and the tank, for returning the treatment liquid filtered by the filtration mechanism to the tank; The liquid delivery system of claim 7 further comprising:

14. a branching portion in the circulation line downstream of the filter, from which a supply line for supplying the processing liquid to a substrate processing unit branches; a valve provided between the filter and the branching portion; a drainage line connected between the filter and the valve in the circulation line; Furthermore, The control unit closes the valve and drains the processing liquid from the drain line before starting circulation of the processing liquid in the circulation line. The liquid supply system according to claim 1 or 2.

15. a tank for storing a processing liquid; a circulation line that returns the treatment liquid sent from the tank to the tank; a pump that generates a circulating flow of the treatment liquid in the circulation line; a filter provided in the circulation line downstream of the pump; a back pressure valve provided in the circulation line downstream of the filter; a control unit that controls each unit; Equipped with When stopping the operation of the pump, the control unit controls the pump and the back pressure valve so that the flow rate of the processing liquid flowing through the circulation line is equal to or less than a given threshold value during the period from when the discharge pressure of the pump starts to decrease until the operation of the pump is stopped. Fluid supply system.

16. a liquid processing section for processing substrates with the processing liquid; a supply line for supplying the processing liquid from the liquid supply system according to claim 1 or 2 to the liquid processing section; A liquid treatment device comprising:

17. a step of operating a pump to form a circulation flow of the treatment liquid in a circulation line that returns the treatment liquid sent from the tank to the tank; decreasing the circulation flow of the treatment liquid in the circulation line; starting a circulation flow of the treatment liquid in the circulation line; Including, The step of decreasing the circulating flow includes: When the operation of the pump is stopped, the pump and a back pressure valve provided downstream of the filter in the circulation line are controlled so that the differential pressure between the upstream side and the downstream side of the filter provided downstream of the pump in the circulation line is equal to or less than a given threshold value during the period from when the discharge pressure of the pump starts to decrease until the operation of the pump is stopped. Liquid supply method.

18. The step of decreasing the circulating flow includes: When the operation of the pump is stopped, the pump and the back pressure valve are controlled so that the differential pressure between the upstream side and the downstream side of the filter is equal to or less than the maximum differential pressure between the upstream side and the downstream side of the filter in the step of forming the circulating flow. The liquid supply method according to claim 17.

19. The step of establishing a circulation flow includes: When starting circulation of the treatment liquid in the circulation line, the pump and the back pressure valve are controlled so that the differential pressure between the upstream side and the downstream side of the filter is equal to or less than the maximum differential pressure between the upstream side and the downstream side of the filter in the step of forming the circulation flow. The liquid supply method according to claim 17 or 18.

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